toning cyanotypes

I have a reference from post-factory photography #5 for a black toner for
cyanotypes - but the author had not tried it, and indicated they did not
know if it works - so I don't know if it works.

It states: "Soak print in a solution containing copper salt. Wash. Immerse
in ammonium sulfide. Or the copper solution can be added to the
sensitizer."

But checked on ammonium sulfide - I beleive it releases hydrogen sulfide
fumes which are toxic. Unless this is done outside or under very good
ventilation - it would likely be more dangerous than using nitric acid.

Also read about doing split toning - where only parts of the image are
toned. Involves using a dilute tannic acid/sodium carbonate toner.
Tones the highlights first - can pull the print from toner and only have
parts of it toned.

Gord

On Fri, 25 Oct 2002 Rustart@aol.com wrote:

> You can get Nitric Acid from Rembrandt Graphic Arts. Here is the uel:
> http://www.rembrandtgraphicarts.com/07_rga_cat.html#Anchor-MORDANTS-49575
> Hope this helps
> Rusty
>
> > Hi:
> >
> > Nitric acid is kind of nasty. I've used tannic acid to tone cyanotypes
> >
> > On Thu, 24 Oct 2002, dennis vinciguerra wrote:
> >
> > > Hello all,
> > > Certain cyanotype images work very well in blue, some in brown but then
> > > there are those that need to be black. The formula I have calls for
> > nitric
> > > acid but I'm not having any luck locating it. Anyone have either a source
> > > or another black toning formula ?
> > >
> > > Thank you,
> > > Dennis
> >
>
>

---------------------------------------------------------
Gordon J. Holtslander Dept. of Biology
holtsg@duke.usask.ca 112 Science Place
http://duke.usask.ca/~holtsg University of Saskatchewan
Tel (306) 966-4433 Saskatoon, Saskatchewan
Fax (306) 966-4461 Canada S7N 5E2
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Received on Sun Oct 27 01:06:40 2002